I'm so sorry for the loss of your husband. My heart goes out to you this Christmas.
It seems so many aren't being taught proper etiquette these days or even merely that such a thing exists. My first thought is that perhaps they're trying to not be offensive or give you painful reminders of your loss (as though you'd forget). It is still proper etiquette to address the widow as Mrs. (surname). It is also proper to address the widow using her first name then surname. (i.e., Mrs. Jane Doe instead of Mrs. John Doe) however, either is acceptable.
Pardon my being forward. I apologize in advance if I'm out of line in offering such advice but I am only doing so because my heart goes out to you. My daughter's mother in law had her first Christmas without her dear husband last year. He was a good man and we were saddened by his loss. I also suffered a loss a few Christmases ago of one of my children. I was devastated and it didn't hit me until the day after Thanksgiving (I'm American) when my husband decided to pull out Christmas decorations. Traditionally, my daughter and I did Christmas together (tree, decorations, shopping for presents, etc). So when he did that, I just died inside. I couldn't bring myself to help him. My sadness was so profound, I sought counseling. I still had two sons in my home and I was really struggling. When we put up the tree, I couldn't be enticed to care about it. I tried to be cheerful for them and let them decorate the tree. Of course, as kids are prone to do, they stuck all the ornaments in one spot on the tree and I couldn't have cared less that year what the tree looked like. I just told them they did a stupendous job and thanked them and left it as it was. They were proud of themselves and that's what mattered.
My therapist said that it often helps to start new traditions during the holidays so that's what we did. We changed some things. It still hurts but not as bad as that Christmas. My sons still aren't adults yet (they're teens now) but they're now "Santa's helpers" for the grands. They now help with shopping and wrapping and putting self assembled toys together.
My dd's mil also started her own tradition of going on holiday during Christmas. She and her husband used to spend Christmas with us. It was too painful for her to be here without her husband. My husband and I have 7 children and 4 grands, so holidays at our house is quite busy. Her only child is married to my daughter so it only made sense we spend our holidays together at our home, rather than impose ourselves at their home.
I wish you peace and comfort this Christmas.